The fixtures were constructed of polyethylene
(an FDA approved plastic for food service) and
machined in the robotics department’s machine
shop. The bun fixture holds eight hot dog buns
and the hot dog fixture holds an equal number of
wieners (unlike the mismatched ratio of hot dogs
to buns in typical grocery store packaging!).

“The hot dog fixture is fitted with an optical
sensor which sends a visual signal via a status light
on top to signal that the machine had to be
reloaded with dogs and buns,” explained
D’Angelo and Laperriere.

“The coolest fixture on the robot is probably
the ketchup and mustard pump. This fixture holds
two pneumatic cylinders that push down on the
pumpers to dispense the condiments.”
The condiment pumping fixture is made of
Bosch tubing pulled from scrap and designed
“on-the-fly,” machined, and assembled to the
robot in about two hours’ time. “We used trial
and error to determine the timing and air pressure
necessary to dispense the right amount of
condiments onto the dogs.”

Arm Choice and Other Parts

The team chose the Adept Cobra 600 because
of its size and also because the Adept robot is
tried and true, used by many in industry over
several years. “The work envelope is sufficient to
do projects such as the hot dog assembly line and
other light manufacturing projects we may choose
to do,” the roboticists explained. The arm is also
just small enough so the team can store the
robot’s computer under the table it sits on. The
entire cell can be moved on casters because of the
robot’s light weight. Other parts include two
Norgren RLD06A SAN A400 single-acting, spring
actuated pneumatic cylinders. “We bought these
from McMaster-Carr to apply a force onto the
condiment pumping fixture.”
The robot employs a double-acting cylinder
used to deliver plates from their storage space
behind the cell glass to each customer. This is an
RHINC base slide powered by an SMC NCGCN25-
1000 air cylinder that is used to transfer each
serving plate from one side of the cell to the other
so the robot can place the hot dog and bun onto
the plate. The slide is also used to maneuver the
hot dog under the condiments so they can pump
across the whole dog. A conveyor brings the plate
to the “home” position so it can be pushed out of
the cell.